The proposed research will study the development and evolution of computer-based personal information files of biomedical research investigators. It will establish a measure of divergence of file information in order to assess the adequacy of group interest profiling and database management as an alternative to individual files. If the interests of individual investigators do not diverge, then members of the research group can efficiently share access to the same database without significant additional cost. An existing timesharing computer system will be used to provide both individual and group information services to medical investigators whose behavior will be the subject to study. The text files maintained by these users of the system will be analyzed to develop measures of divergence of their interests. Objectives are: 1. to measure the divergence of individual research investigators' personal information files from a master information file covering the common interests of a group of investigators working in the same subject area; 2. to measure the divergence of individual information files from one another; 3. to determine a relationship between the divergence index of individual investigators and their need for individual versus common files; and 4. to identify characteristics of research investigators, such as word usage in their research publications, that can predict divergence of research interests.